import random

send = {'1':'a','2':'b','3':'c'}
receive = {'1':'a','2':'b','3':'c'}
gift={'a','b','c'}
for i in receive.keys():
    cur_gift = receive.get(i)
    gift.discard(cur_gift)
    result = gift.pop()
    print(result)
    receive[i] = result
    gift.add(cur_gift)
    # print(receive)
    # print(gift)
for i in receive.keys():
    print(f"{send.get(i)}-->{receive.get(i)}")






